WO2020195473A1 - Electromagnetic wave measurement point calculation program and radiation interference wave measurement device - Google Patents

Abstract

This electromagnetic wave measurement point calculation program causes a computer to execute a correction coefficient calculation function for using the positional relationship between an object under test including a radiation source that emits radiation interference waves and an antenna for measuring at least one from among the electric field and magnetic field of the radiation interference waves to calculate a correction coefficient for making the height interval of the antenna satisfy the sampling theorem and a measurement height calculation function for using the correction coefficient to sequentially calculate the height of the antenna during the measurement.

Description

Electromagnetic wave measurement point calculation program and radiation interference wave measurement device

The present invention relates to an electromagnetic wave measurement point calculation program and a radiated interfering wave measuring device.
The present application claims priority based on Japanese Patent Application No. 2019-060380 filed in Japan on March 27, 2019, the contents of which are incorporated herein by reference.

Electronic devices may emit radiant interference waves, which are electromagnetic waves that affect surrounding electronic devices and communication devices. For this reason, it is now necessary to conduct a radiated jamming test to confirm that the electric field strength of the radiated jamming wave is below the permissible value of the internationally established standard before the electronic device is shipped to the market. ..

In the radiated interference wave test, the electric field strength is measured by the antenna while changing the height of the antenna based on the radiation source of the radiated interference wave and the orientation of the antenna based on the radiation source, and the position where the electric field strength is maximized is determined. Explore. Then, at the position where the electric field strength is maximum, the electric field strength of the radiated interfering wave is measured for a certain period of time, and it is confirmed whether or not the measured value of the electric field strength is equal to or less than the permissible value of the internationally established standard. ..

Examples of the device for performing such a radiated interference wave test include the radiated interference wave measuring device described in Patent Document 1.

JP-A-2017-181104

In order to search for the position where the electric field strength is maximum, it is necessary to measure the electric field distribution by changing the height of the antenna and the angle of the turntable on which the specimen is placed one by one. Therefore, in the radiated interference wave test, it is necessary to measure the electric field strength at each of a huge number of measurement points. For example, taking radiated interfering wave measurement in which the frequency band of information and communication equipment, 30 MHz to 40 GHz, is the frequency range to be measured, the height of the antenna is changed from 1 m to 4 m, and the specimen is placed. It is necessary to change the angle of the turntable from 0 degrees to 360 degrees. In this case, when the radiation jamming test is performed with the antenna height at 1 cm intervals and the turntable angle at 1 degree intervals, the number of measurement points becomes enormous, about 140,000, which is necessary for conducting the radiation jamming test. Time will be very long.

Further, in such a radiation interference test, since it is necessary to detect the maximum electric field strength position in a wide frequency band, a spectrum analyzer capable of measuring a spectrum in a wide frequency band is used. Examples of such a spectrum analyzer include a superheterodyne type spectrum analyzer and an FFT (Fast Fourier Transform) type spectrum analyzer. However, measuring the spectrum in a wide frequency band further increases the time required to carry out the radiated jamming test.

In this way, the work of searching for the height of the antenna and the angle of the turntable that maximizes the electric field strength requires a great deal of time. Therefore, the radiation interference wave measuring device disclosed in Patent Document 1 measures the electric field intensity distribution of the radiation interference wave at the measurement points set at the measurement interval of 1/2 or less of the wavelength of the radiation interference wave. By interpolating the electric field strength between the measurement points, the number of measurement points is reduced and the time required to carry out the radiated interference wave test is shortened.

However, since the radiation interference wave measuring device disclosed in Patent Document 1 does not optimize the interval between measurement points, it may not be possible to sufficiently shorten the time required to carry out the radiation interference wave test. Further, when the frequency of the radiated interference wave is high, the wavelength of the radiated interference wave becomes short. Therefore, for example, the frequency of the radiated interfering wave is 10 GHz, the horizontal distance between the antenna and the specimen is 3 m, the height of the antenna is changed from 1 m to 4 m, and the turn on which the specimen is placed. When the radiated jamming test is performed by changing the table angle from 0 degrees to 360 degrees, the number of measurement points becomes enormous, about 250,000, and the time required to carry out the radiated jamming test is very long. turn into.

Therefore, it is an object of the present invention to provide an electromagnetic wave measurement point calculation program and a radiation interference wave measuring device capable of shortening the time required for carrying out the radiation interference wave test.

One aspect of the present invention includes a relative positional relationship between a specimen including a radiation source that emits a radiating interfering wave and an antenna that performs measurement of at least one of an electric field and a magnetic field of the radiating interfering wave, and the specimen. The measurement using the correction coefficient calculation function for calculating the correction coefficient in which the height interval of the antenna satisfies the sampling theorem based on the reflection coefficient of the radiated electromagnetic wave on the placed floor surface, and the correction coefficient. This is an electromagnetic wave measurement point calculation program that causes a computer to execute a measurement height calculation function that sequentially calculates the height of the antenna when the above is executed.

Further, in one aspect of the present invention, the correction coefficient calculation function includes the shortest horizontal distance between the specimen and the antenna, the longest horizontal distance between the specimen and the antenna, and the specimen is placed. With the function of calculating the correction coefficient using at least two of the shortest distance from the floor surface to the specimen and the longest distance from the floor surface on which the specimen is placed to the specimen. is there.

Further, in one aspect of the present invention, the correction coefficient calculation function calculates the correction coefficient using the following equation (1) or equation (2) and equation (3), and calculates the measurement height. The function sequentially calculates the height of the antenna when the measurement is performed using the following equation (4).

K _hmax : Correction coefficient h _rx : Antenna height d _min : Shortest horizontal distance between the specimen and the antenna d _max : _Longest horizontal distance between the specimen and the antenna h _min : The specimen is placed The shortest distance from the floor surface to the specimen h _max : The longest distance from the floor surface on which the specimen is placed to the specimen Δh _rx : The amount of change in the height of the antenna

h _{rx_min} : Minimum value of antenna height

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program causes the computer to further execute a determination function for determining whether or not it is necessary to consider the radiation interference wave reflected on the floor surface, and the correction is performed. When it is determined that it is not necessary to consider the radiated electromagnetic wave reflected on the floor surface, the coefficient calculation function calculates the correction coefficient using the equation (1).

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program causes the computer to further execute a determination function for determining whether or not it is necessary to consider the radiation interference wave reflected on the floor surface, and the correction is performed. When the coefficient calculation function determines that it is necessary to consider the radiated electromagnetic wave reflected on the floor surface, the coefficient calculation function calculates the correction coefficient using the equation (2), or calculates the correction coefficient. To cancel.

Further, in one aspect of the present invention, the correction coefficient calculation function is corrected by using the equation (2) regardless of whether or not it is necessary to consider the radiated interfering wave reflected on the floor surface. Calculate the coefficient.

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program is the distribution of at least one of the electric field and the magnetic field of the radiated interfering wave, and the first electromagnetic field that acquires the first electromagnetic field distribution obtained by simulation or actual measurement. The electric field or electromagnetic field at the height of the antenna calculated by the field distribution acquisition function and the measurement height calculation function is acquired by simulation or actual measurement, and is calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function for acquiring the second electromagnetic field distribution obtained by interpolating the electric field or the magnetic field at the height of the antenna different from the height of the antenna is further executed by the computer, and the determination function is performed. , The deviation between the maximum value of the electric field or the magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or the magnetic field in the second electromagnetic field distribution is calculated, and when the deviation is equal to or less than a predetermined allowable value, the floor. This is a function for determining that it is not necessary to consider the electromagnetic interference wave reflected by the surface.

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program is the distribution of at least one of the electric field and the magnetic field of the radiated interfering wave, and the first electromagnetic field that acquires the first electromagnetic field distribution obtained by simulation or actual measurement. The electric field or electromagnetic field at the height of the antenna calculated by the field distribution acquisition function and the measurement height calculation function is acquired by simulation or actual measurement, and is calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function for acquiring the second electromagnetic field distribution obtained by interpolating the electric field or the magnetic field at the height of the antenna different from the height of the antenna is further executed by the computer, and the determination function is performed. , The deviation between the maximum value of the electric field or the magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or the magnetic field in the second electromagnetic field distribution is calculated, and when the deviation exceeds a predetermined allowable value, the said This is a function for determining that it is necessary to consider the electromagnetic interference wave reflected on the floor surface.

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program is the distribution of at least one of the electric field and the magnetic field of the radiated interfering wave, and the first electromagnetic field that acquires the first electromagnetic field distribution obtained by simulation or actual measurement. The electric field or electromagnetic field at the height of the antenna calculated by the field distribution acquisition function and the measurement height calculation function is acquired by simulation or actual measurement, and is calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function for acquiring the second electromagnetic field distribution obtained by interpolating the electric field or the magnetic field at the height of the antenna different from the height of the antenna is further executed by the computer, and the determination function is performed. , The deviation between the maximum value of the electric field or the magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or the magnetic field in the second electromagnetic field distribution is calculated, and the deviation corresponds to the reflection coefficient which is equal to or less than a predetermined threshold value. If this is the case, it is a function of determining that it is not necessary to consider the electromagnetic interference wave reflected on the floor surface.

Further, in one aspect of the present invention, the electromagnetic wave measurement point calculation program is the distribution of at least one of the electric field and the magnetic field of the radiated interfering wave, and the first electromagnetic field that acquires the first electromagnetic field distribution obtained by simulation or actual measurement. The electric field or electromagnetic field at the height of the antenna calculated by the field distribution acquisition function and the measurement height calculation function is acquired by simulation or actual measurement, and is calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function for acquiring the second electromagnetic field distribution obtained by interpolating the electric field or the magnetic field at the height of the antenna different from the height of the antenna is further executed by the computer, and the determination function is performed. , The deviation between the maximum value of the electric field or the magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or the magnetic field in the second electromagnetic field distribution is calculated, and the deviation corresponds to the reflection coefficient exceeding a predetermined threshold value. If this is the case, it is a function of determining that it is necessary to consider the electromagnetic interference wave reflected on the floor surface.

Further, in one aspect of the present invention, the determination function is performed when the sampling frequency calculated from the reflection coefficient, the frequency of the radiating interfering wave and the maximum frequency of the radiating interfering wave satisfies the following equation (5). This is a function for determining that it is not necessary to consider the radiated interfering wave reflected on the floor surface.

Further, in one aspect of the present invention, in the determination function, when the sampling frequency calculated from the reflection coefficient, the frequency of the radiating interfering wave and the maximum frequency of the radiating interfering wave does not satisfy the following equation (6). , It is a function of determining that it is necessary to consider the radiated interfering wave reflected on the floor surface.

Further, in one aspect of the present invention, the determination function is performed when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave at which at least one of the electric field and the magnetic field is measured satisfies the following equation (7). This is a function for determining that it is not necessary to consider the radiated interfering wave reflected on the floor surface.

Further, in one aspect of the present invention, the determination function is when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave at which at least one of the electric field and the magnetic field is measured does not satisfy the following equation (8). This is a function for determining that it is necessary to consider the radiated interfering wave reflected on the floor surface.

Further, in one aspect of the present invention, the determination function includes a radio wave absorber having a height of 0.45λ _{min or} 2.8λ _max with respect to the floor surface, whichever is larger than the larger value. When it is laid on the floor surface, it is a function of determining that it is not necessary to consider the radiation interference wave reflected on the floor surface.

Further, in one aspect of the present invention, in the determination function, a radio wave absorber having a height of 0.45 λ _min and 2.8 λ _max , which is less than the larger value with respect to the floor surface, is laid on the floor surface. This is a function for determining that it is necessary to consider the radiated interfering wave reflected on the floor surface when the radio wave absorber is installed or the radio wave absorber is not laid.

Further, in one aspect of the present invention, the radiation interference wave measuring device includes a computer that executes any one of the above-mentioned electromagnetic wave measuring point calculation programs.

According to the present invention, the time required to carry out the radiated interfering wave test can be shortened.

It is a figure which shows the example of the structure of the radiated interference wave measuring apparatus which concerns on embodiment. It is a figure which shows the example of the measurement point located on the surface which surrounds the specimen which concerns on embodiment. A low-pass filter is applied to the first electric field distribution and the first electric field strength distribution reproduced by simulation when the height dimension of the specimen according to the embodiment is 100 cm and the shortest distance from the floor surface to the specimen is 10 cm. It is a figure which shows the example of the 2nd electric field distribution obtained by applying and interpolating. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first electric field. It is a figure which shows the example of the relationship between the maximum value of a distribution, and the deviation of the maximum value of a second electric field distribution. It is a figure which shows the example of the relationship between the reflection coefficient of the floor surface which concerns on embodiment, and the quantity obtained by standardizing the frequency of the radiation interference wave for measuring the electric field strength with a sampling frequency. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first It is a figure which shows the example of the relationship between the maximum value of one electric field distribution and the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first It is a figure which shows the example of the relationship between the maximum value of one electric field distribution and the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is horizontally polarized, and the first It is a figure which shows the example of the relationship between the maximum value of one electric field distribution and the maximum value of a second electric field distribution. The height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, the reflection coefficient of the floor surface when the radiated interfering wave is vertically polarized, and the first It is a figure which shows the example of the relationship between the maximum value of one electric field distribution and the maximum value of a second electric field distribution. It is a figure which shows a part example of the electric field strength distribution before interpolation which concerns on embodiment. It is a figure which shows a part example of the electric field strength distribution after interpolation which concerns on embodiment. It is a figure which shows the example of the hardware composition of the control part which concerns on embodiment. It is a flowchart which shows the example of the process executed by the radiation interference wave measuring apparatus which concerns on embodiment. It is a flowchart which shows the example of the process which selects the formula which calculates the correction coefficient by the radiation interference wave measuring apparatus which concerns on embodiment.

[Embodiment]
The radiation interference wave measuring device according to the embodiment will be described with reference to FIGS. 1 to 21. FIG. 1 is a diagram showing an example of a configuration of a radiation interference wave measuring device according to an embodiment.

The radiation jamming wave measuring device 1 shown in FIG. 1 is, for example, a device used for a radiation jamming wave test for measuring a radiation jamming wave emitted from a specimen 100, which is a specimen, in accordance with an EMC standard. The test conditions and test methods for this radiated disturbance test are internationally defined. The radiation interference wave measuring device 1 is arranged in an anechoic chamber provided with a metal floor surface forming a ground plane. A radio wave absorber is attached to the inner wall of the anechoic chamber excluding the metal floor. Further, the specimen 100 is, for example, an electronic device, and includes a radiation source that emits a radiating interfering wave.

As shown in FIG. 1, the radiation interference wave measuring device 1 includes an antenna 11, an antenna mast 12, a turntable 13, a radio wave absorber 14, a controller 15, a control unit 20, and a receiving unit 30. ..

The antenna 11 receives the radiated interfering wave in a predetermined frequency band at the measurement point located on the surface surrounding the specimen 100. FIG. 2 is a diagram showing an example of measurement points located on a surface surrounding the specimen according to the embodiment. This surface is, for example, the side surface of a cylinder whose central axis is perpendicular to the ground plane and which contains the specimen 100 and the base 200 inside. As shown by white circles in FIG. 2, each measurement point is formed by a first axis along the circumferential direction of the circle on the bottom surface of the cylinder and a second axis parallel to the central axis of the cylinder. It is arranged on the specified two-dimensional Cartesian coordinates. The first axis shows the height of each measurement point with respect to the specimen 100. The second axis shows the angle of each measurement point with respect to the specimen 100. Further, the measurement points shown in FIG. 2 are arranged at equal intervals in a direction parallel to the first axis and a direction parallel to the second axis. However, the measurement points shown in FIG. 2 may be arranged at arbitrary intervals in at least one of the direction parallel to the first axis and the direction parallel to the second axis.

The antenna mast 12 supports the antenna 11 in a form that allows it to be raised and lowered, and is arranged at a predetermined distance from the specimen 100. The turntable 13 is a disk-shaped turntable provided on the ground plane, and can rotate about an axis perpendicular to the ground plane. The specimen 100 is placed on a table 200 placed on the turntable 13. The radio wave absorber 14 is a pyramidal structure laid on the ground plane, and is made of a material that absorbs radiated interfering waves, for example, a foam material.

The controller 15 includes a height changing unit 151 and an azimuth changing unit 152. The height changing unit 151 executes a height changing process for changing the height of the antenna 11 that receives the radiation interference wave radiated by the specimen 100 with respect to the specimen 100. Specifically, the height changing unit 151 drives the antenna mast 12 to raise and lower the antenna 11 to fix the antenna 11 at a predetermined height. The azimuth changing unit 152 executes an azimuth changing process for changing the azimuth of the antenna 11 with reference to the specimen 100. Specifically, the orientation changing unit 152 drives the turntable 13 to rotate the specimen 100 and the table 200 by 360 degrees after the antenna 11 is fixed to a predetermined height by the height changing unit 151.

The control unit 20 includes a determination function 201, a correction coefficient calculation function 202, a measurement height calculation function 203, a first electromagnetic field distribution acquisition function 204, and a second electromagnetic field distribution acquisition function 205.

The determination function 201 is a function for determining whether or not it is necessary to consider the radiated interference wave reflected on the floor surface. About a specific example when the determination function 201 determines that it is not necessary to consider the radiated interference wave reflected on the floor surface and a specific example when it is determined that it is necessary to consider the radiated interference wave reflected on the floor surface. Will be described later.

In the correction coefficient calculation function 202, the relative positional relationship between the specimen 100 including the radiation source that emits the radiated interfering wave and the antenna 11 that executes the measurement of the electric field strength of the radiated interfering wave and the specimen 100 are placed. This is a function of calculating a correction coefficient in which the height interval of the antenna 11 satisfies the sampling theorem based on the reflection coefficient of the radiated interfering wave on the floor surface. Specifically, the correction coefficient calculation function 202 sets the relative positional relationship between the specimen 100 and the antenna 11, the shortest distance in the horizontal direction between the specimen 100 and the antenna 11, and the horizontal between the specimen 100 and the antenna 11. Use at least two of the longest distance in the direction, the shortest distance from the floor on which the specimen 100 is placed to the specimen 100, and the longest distance from the floor on which the specimen 100 is placed to the specimen 100. To do. For example, the correction coefficient calculation function 202 calculates the correction coefficient based on the principle described below.

The electric field E at an arbitrary point is expressed by the following equation (9).

The square of the electric field strength is expressed by the following equation (10) in consideration of the equation (9). Equation (10), the distance _r n argument n indicating the radiation source, m, and the antenna 11 and the radiation source, _{r m,} coefficients _{a n, a m, b n} , b m, wavenumber k, the number of specimen 100 Contains N. Further, Equation (10) shows that the electric field strength is the sum of a sine wave that oscillates with respect to r _n -r _m.

The wave number k is 2π divided by the measurement frequency. Therefore, the radiation interference wave measuring device 1 can completely reproduce the electric field intensity distribution by measuring the electric field intensity of the radiation interference wave at intervals satisfying the condition of the following equation (11) based on the sampling theorem. it can. Here, λ is the wavelength of the radiation interference wave for which the radiation interference wave measuring device 1 measures the electric field strength.

The distance _r n between the antenna 11 and the radiation source, to represent the _{r m} as a function of the height _{h rx} antenna 11 becomes as the following equation (12) and (13). Equation (12), the height of the horizontal distance d _n, the vertical position of the radiation source n h _n and the antenna 11 of the antenna 11 and the distance r _n is the antenna 11 of the source n and source n It is shown that it is represented by h _rx . Similarly, equation (13), horizontal distance _{d m} between the distance _{r m} is the antenna 11 of the antenna 11 and the radiation source m radiation source m, the height direction of the radiation source m position _{h m} and antenna 11 It is shown that the height of is represented by h _rx .

Further, the height direction position h _m of the position in the height direction h _n and radiation sources m of the radiation source n, if there is radiation interference wave is reflected by the floor, take positive and negative values by the mirror image principle, floor If there are no radiated jamming waves reflected by the surface, only positive values are taken. In the following description, it is assumed that the position h _n in the height direction of the radiation source _n is lower than the position h _m in the height direction of the radiation source m.

On the other _hand, the relationship between r n of change -r _m delta _(r n -r _m) and antenna height _{h rx} is expressed by the following equation (14) and (15). Here, Δh _rx is the amount of change in the height h _rx of the antenna. Further, K _h is a correction coefficient.

Further, the following equations (16), (17), (18) and (19) are established.

Considering the equations (16), (17), (18) and (19) and the dimensions of the specimen 100, the following equation (20) is established.

Further, when the height interval of the antenna 11 that executes the measurement of the electric field strength of the radiated interfering wave emitted from the radiation source included in the specimen 100 satisfies the following equation (21), the sampling theorem is satisfied.

Further, it is necessary that the following equation (22) describing the characteristics regarding the direction in which the radiation source included in the specimen 100 emits the radiating interfering wave is established. Equation (22), the wave number k is zero, an equation coefficients _a n included in expression (9) described _above, a m, _{b n} and _{b m} are consideration of the case is a triangular function. Here, h _{rx_min} is the minimum value of the height of the antenna 11.

Up to this point, the case where there is no radiated interference wave reflected on the floor surface has been described. On the other hand, when there is a radiation interference wave reflected on the floor surface, the height position h _n of the radiation source _n and the height position h _{m of the} radiation source m take not only positive values but also negative values. By considering the _acquisition , the correction coefficient K _hmax can be calculated under the conditions of the equations (16), (17), (18) and (19). Considering this condition, the following equation (23) is established in which h _min included in the above equation (20) is replaced with −h _max .

That is, the correction coefficient calculation function 202 calculates the correction coefficient K _hmax using the above equation (20) when there is no radiation interference wave reflected on the floor surface, and the radiation interference wave reflected on the floor surface is _generated. In some cases, it is preferable to calculate the correction coefficient K _hmax using the above equation (20). In other words, the correction coefficient calculation function 202 may calculate the correction coefficient using the equation (20) when it is determined by the determination function 201 that it is not necessary to consider the radiated interference wave reflected on the floor surface. preferable. Similarly, when it is determined by the determination function 201 that it is necessary to consider the radiation interference wave reflected on the floor surface, the correction coefficient calculation function 202 may calculate the correction coefficient using the equation (23). preferable.

The measurement height calculation function 203 sequentially calculates the height of the antenna 11 when the measurement is executed using the correction coefficient K _hmax calculated by the correction coefficient calculation function 202. Specifically, the measurement height calculation function 203 sequentially calculates the height of the antenna 11 when the measurement is executed using the following equation (24).

That is, the measurement height calculation function 203 uses the above-mentioned equations (20), (21) and (22), or the above-mentioned equations (23), (21) and (22). By using it, the height interval Δh _rx (h _rx ) of the antenna 11 when the measurement is performed so that K _hmax Δh _rx (h _rx ) becomes constant is calculated. Then, the measurement height calculation function 203 calculates the height of each measurement point using the equation (24).

Next, a specific example in which the determination function 201 determines that it is not necessary to consider the radiation interference wave reflected on the floor surface and a case in which it is determined that it is necessary to consider the radiation interference wave reflected on the floor surface. A specific example will be described.

The first electromagnetic field distribution acquisition function 204 is an electric field intensity distribution from a radiation source set assuming a radiation interference wave or a radiation interference wave, and acquires the first electric field distribution obtained by simulation or actual measurement.

The second electromagnetic field distribution acquisition function 205 acquires the electric field strength at the height of the antenna 11 calculated by the measurement height calculation function 203 from the first electric field strength distribution, and uses a low-pass filter to calculate the measurement height. The second electric field distribution obtained by interpolating the electric field strength at the height of the antenna 11 different from the height of the antenna 11 calculated by 203 is acquired.

FIG. 3 shows the first electric field distribution and the first electric field reproduced by simulation or actual measurement when the height dimension of the specimen according to the embodiment is 100 cm and the shortest distance from the floor surface to the specimen is 10 cm. It is a figure which shows the example of the 2nd electric field distribution obtained by applying the low-pass filter to the intensity distribution and interpolating. This first electric field distribution is arranged one by one at the highest height position and the lowest height position of the height dimension of the specimen 100 among the specimens 100, and the amplitude and phase of the radiated interfering waves radiated. Is a distribution obtained by simulation or measurement performed under the assumption that there are equal sources of radiation. The dotted line in FIG. 3 shows the first electric field distribution. The solid line in FIG. 3 shows the second electric field distribution.

In both the first electric field distribution and the second electric field distribution, the electric field strength is plotted with the height interval of the antenna 11 as 1 cm. However, the second electric field strength distribution is interpolated by using the result of simulation or actual measurement of the first electric field distribution only at 43 points and applying a low-pass filter at other measurement points.

Comparing the first electric field distribution shown by the dotted line in FIG. 3 with the second electric field distribution shown by the solid line in FIG. 3, it can be seen that the height of the peak and the height of the null point are well reproduced. .. Here, the null point means the height of the antenna 11 at which the electric field strength is minimized. Moreover, when comparing the two, it can be seen that the magnitude of the electric field strength at the peak height is also well reproduced. Therefore, the second electric field distribution is considered to be sufficiently reliable. Comparing the two, there are some places where the magnitude of the electric field strength at the null point is not sufficiently reproduced, but there is no particular problem because the magnitude of the electric field strength at the null point is not used in the radiation interference test.

FIG. 4 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, and the radiated interfering wave is horizontally polarized. , Is a diagram showing an example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 5 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiation interference wave for measuring the electric field strength is 6 GHz, and the radiation interference wave is vertically polarized. , It is a figure which shows the example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 6 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, and the radiated interfering wave is horizontally polarized. , Is a diagram showing an example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 7 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 6 GHz, and the radiated interfering wave is vertically polarized. , It is a figure which shows the example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution.

In each of FIGS. 4 to 7, the horizontal axis shows the reflection coefficient of the floor surface, and the vertical axis shows the deviation between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. Further, FIGS. 4 to 7 show four or five data in which the shortest distance from the floor surface to the specimen 100 is different. Further, FIGS. 4 to 7 are views in the case where the frequency of the radiated interfering wave whose electric field strength is measured and the sampling frequency are equal to each other.

In the case of FIG. 4, when the reflectance coefficient of the floor surface is about 0.01 or less, the deviation converges to 0.3 dB or less regardless of the shortest distance from the floor surface to the specimen 100. In the case of FIG. 5, when the reflectance coefficient of the floor surface is about 0.01 or less, the deviation converges to 0.5 dB or less regardless of the shortest distance from the floor surface to the specimen 100. In the case of FIG. 6 and FIG. 7, when the reflectance coefficient of the floor surface is about 0.01 or less, the deviation converges to 0.3 dB or less regardless of the shortest distance from the floor surface to the specimen 100. .. That is, when the reflection coefficient of the floor surface is 0.01 or less, it can be said that there is no problem in determining that it is not necessary to consider the reflection coefficient of the floor surface. Further, here, the frequency of the radiated interfering wave for measuring the electric field strength was examined at 6 GHz, but the same can be said for other frequencies as long as the sampling frequency and the measurement frequency are the same frequency. it is conceivable that.

Therefore, the determination function 201 calculates the deviation between the maximum value of the electric field in the first electric field distribution and the maximum value of the electric field in the second electric field distribution, and when the deviation is equal to or less than a predetermined allowable value, it is reflected on the floor surface. It is determined that it is not necessary to consider the radiation interference wave to be generated. Alternatively, the determination function 201 calculates the deviation between the maximum value of the electric field in the first electric field distribution and the maximum value of the electric field in the second electric field distribution, and if the deviation exceeds a predetermined allowable value, on the floor surface. Judge that it is necessary to consider the reflected radiated interference wave.

Next, the case where the frequency of the radiated interfering wave whose electric field strength is measured and the sampling frequency are different will be described.

FIG. 8 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, and the radiated interfering wave is horizontally polarized. , Is a diagram showing an example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 9 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiation interference wave for measuring the electric field strength is 1 GHz, and the radiation interference wave is vertically polarized. , It is a figure which shows the example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 10 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 1 GHz, and the radiated interfering wave is horizontally polarized. , Is a diagram showing an example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 11 shows the reflection coefficient of the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiation interference wave for measuring the electric field strength is 1 GHz, and the radiation interference wave is vertically polarized. , It is a figure which shows the example of the relationship between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution.

In any of FIGS. 8 to 11, when the reflectance coefficient of the floor surface is about 0.1 or less, the deviation converges to 0.1 dB or less regardless of the shortest distance from the floor surface to the specimen 100. ..

Therefore, the determination function 201 calculates the deviation between the maximum value of the electric field in the first electric field distribution and the maximum value of the electric field in the second electromagnetic field distribution, and the deviation corresponds to a reflection coefficient equal to or less than a predetermined threshold value. , Judge that it is not necessary to consider the radiated interference wave reflected on the floor surface. Alternatively, the determination function 201 calculates the deviation between the maximum value of the electric field in the first electric field distribution and the maximum value of the electric field in the second electric field distribution, and when the deviation corresponds to a reflection coefficient exceeding a predetermined threshold value, Judge that it is necessary to consider the radiated interference wave reflected on the floor surface. For example, the determination function 201 determines whether or not the reflection coefficient input by the user using the mouse, keyboard, or the like is equal to or less than the predetermined threshold value using the graph of FIG. 4 or the like obtained by simulation. To do.

Next, the reflectance coefficient Γ of the floor surface required for the deviation to converge with respect to the amount obtained by normalizing the frequency f of the radiated interfering wave whose electric field strength is measured by the sampling frequency f _max will be described. FIG. 12 is a diagram showing an example of the relationship between the reflection coefficient of the floor surface according to the embodiment and the amount obtained by standardizing the frequency of the radiated interfering wave for measuring the electric field strength with the sampling frequency. In FIG. 12, the horizontal axis shows the amount of the frequency f of the radiated interfering wave whose electric field strength is measured, which is normalized by the sampling frequency f _max , and the vertical axis shows −20 * log ₁₀ Γ. When the condition corresponding to the shaded portion in FIG. 12 is satisfied, that is, when the condition satisfying the following equation (25) is satisfied, it can be said that the above-mentioned deviation has converged to a sufficiently small value.

Further, the reliability of the above-mentioned equation (25) will be considered with reference to FIGS. 13 to 16. FIG. 13 shows the reflection of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, and the radiated interfering wave is horizontally polarized. It is a figure which shows the example of the relationship between the coefficient and the deviation between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 14 shows the reflection of the floor surface when the height dimension of the specimen according to the embodiment is 100 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, and the radiated interfering wave is vertically polarized. It is a figure which shows the example of the relationship between the coefficient and the deviation between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 15 shows reflection on the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, and the radiated interfering wave is horizontally polarized. It is a figure which shows the example of the relationship between the coefficient and the deviation between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution. FIG. 16 shows the reflection of the floor surface when the height dimension of the specimen according to the embodiment is 20 cm, the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, and the radiated interfering wave is vertically polarized. It is a figure which shows the example of the relationship between the coefficient and the deviation between the maximum value of the first electric field distribution and the maximum value of the second electric field distribution.

When the frequency of the radiated interfering wave for measuring the electric field strength is 3.5 GHz, the reflectance coefficient of the floor surface calculated from the above equation (25) is 0.0316 or less. In the case of FIG. 13 and FIG. 14, when the reflectance coefficient of the floor surface is about 0.06 or less, the deviation converges to 0.2 dB or less regardless of the shortest distance from the floor surface to the specimen 100. In the case of FIG. 15 and FIG. 16, when the reflectance coefficient of the floor surface is about 0.06 or less, the deviation converges to 0.6 dB or less regardless of the shortest distance from the floor surface to the specimen 100. Therefore, it can be said that the above-mentioned equation (25) is sufficiently reliable.

Here, the determination function 201 is reflected on the floor surface when the sampling frequency calculated from the reflection coefficient of the floor surface, the frequency of the radiation interference wave and the maximum frequency of the radiation interference wave satisfies the above-mentioned equation (25). Judge that it is not necessary to consider the radiated interference wave. Alternatively, the determination function 201 is reflected on the floor surface when the sampling frequency calculated from the reflection coefficient of the floor surface, the frequency of the radiated interfering wave and the maximum frequency of the radiated interfering wave does not satisfy the above-mentioned equation (25). Judge that it is necessary to consider the radiated interference wave.

From the explanation so far, it can be seen that if the reflectance coefficient of the floor surface is sufficiently small, it is not necessary to consider the radiation interference wave reflected on the floor surface. Further, as described above, when the frequency of the radiated interfering wave reflected on the floor surface is equal to the sampling frequency, the reflection coefficient of the floor surface is preferably 0.01 or less. Further, the following equation (26) obtained by converting the above equation (25) into the absorption characteristics of the radiated interfering waves on the floor surface may be used.

Using the above equations (25) and (26), if the frequency of the radiated interference wave reflected on the floor surface is equal to the sampling frequency, the absorption characteristic of the radiated interference wave on the floor surface must be 40 dB or more. It turns out that there is. When the frequency of the radiated interference wave reflected on the floor surface is lower than the sampling frequency, the absorption characteristic of the radiated interference wave on the floor surface is calculated by substituting the frequency and the sampling frequency into the above equation (25). It turns out that more than the value is required. Examples of the radio wave absorber satisfying such conditions include the radio wave absorber 14 described above. By laying these on the floor surface, the above-mentioned equation (26) is satisfied.

Therefore, when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave for which the electric field measurement is performed satisfies the above-mentioned equation (26), the determination function 201 needs to consider the radiated interfering wave reflected on the floor surface. Judge that there is no. Alternatively, the determination function needs to consider the radiated interfering wave reflected by the floor surface when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave at which the measurement of the electric field is performed does not satisfy the above equation (26). Judge that there is.

Further, when a radio wave absorber having a height of 0.45 λ _{min or} 2.8 λ _max with respect to the floor surface, whichever is larger than the larger value, is laid on the floor surface, at least one of the above conditions is satisfied. It is thought that it is. Here, λ _min is a wavelength corresponding to the minimum value of the frequency of the radiated interfering wave for measuring the electric field strength. Further, λ _max is a wavelength corresponding to the sampling frequency, which is the maximum value of the frequency of the radiated interfering wave for measuring the electric field strength. Therefore, the determination function 201 reflects on the floor surface when a radio wave absorber having a height of 0.45λ _{min or} 2.8λ _max with respect to the floor surface, whichever is larger than the larger value, is laid on the floor surface. It is determined that it is not necessary to consider the radiation interference wave to be generated. Alternatively, in the determination function 201, when a radio wave absorber whose height with respect to the floor surface is less than the larger value of 0.45λ _min and 2.8λ _max is laid on the floor surface, or the radio wave absorber is installed. If it is not laid, it is judged that it is necessary to consider the radio wave interference reflected on the floor surface.

FIG. 17 is a diagram showing a part of an example of the electric field strength distribution before interpolation according to the embodiment. The radiation interference wave measuring device 1 measures the electric field strength of the radiation interference wave at the height of the antenna 11 sequentially calculated based on the correction coefficient K _hmax calculated by using the above equation (20) or equation (23). Then, for example, the electric field strength before interpolation shown in FIG. 17 is acquired. The white circles in FIG. 17 indicate the electric field strength measured at this interval. The black circle in FIG. 17 indicates the interpolated zero.

FIG. 18 is a diagram showing a part of an example of the electric field strength distribution after interpolation according to the embodiment. The radiated interfering wave measuring device 1 applies the low-pass filter having a cutoff frequency equal to the frequency of the radiated interfering wave on which the measurement of the electric field is performed to the pre-interpolation electric field strength shown in FIG. Generates after-field strength. The white circles in FIG. 18 show the same electric field strength as the white circles in FIG. The black circles in FIG. 18 indicate the electric field strength reproduced by applying the low-pass filter and interpolating.

The receiving unit 30 is, for example, a superheterodyne type spectrum analyzer and an FFT type spectrum analyzer. The receiving unit 30 executes a measurement process for measuring the electric field strength in a predetermined frequency band at a measurement point located on a surface surrounding the specimen 100. Then, the receiving unit 30 measures the electric field strength for a certain period of time at the measurement point where the maximum electric field strength is measured.

FIG. 19 is a diagram showing an example of the hardware configuration of the control unit according to the embodiment. As shown in FIG. 19, the control unit 20 includes a main control unit 210, an input device 220, an output device 230, a storage device 240, and a bus 250.

The main control unit 210 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory), controls data transmission / reception between the input device 220, the output device 230, and the storage device 240, and controls the transmission / reception of data between the output device 230 and the output device 230. Controls the operation of the storage device 240.

The input device 220 is a device used for inputting data necessary for operating the radiation interference wave measuring device 1, for example, a keyboard, a mouse, and a touch panel.

The output device 230 is a device used for outputting information related to the operation of the radiated interference wave measuring device 1, for example, a display.

The storage device 240 is a device used for storing data, for example, a hard disk device or an optical disk device. Further, the storage device 240 includes a storage medium 245, stores data in the storage medium 245, and reads data from the storage medium 245. The storage medium 245 is a storage medium used for storing data, for example, a hard disk or an optical disk. Further, the storage medium 245 stores programs that realize each of the determination function 201, the correction coefficient calculation function 202, the measurement height calculation function 203, the first electromagnetic field distribution acquisition function 204, and the second electromagnetic field distribution acquisition function 205. There is. In this case, the main control unit 210 realizes the functions of the determination function 201, the correction coefficient calculation function 202, and the measurement height calculation function 203 by reading and executing these programs.

The bus 250 connects the main control unit 210, the input device 220, the output device 230, and the storage device 240 so as to be able to communicate with each other.

Next, an example of the operation of the radiation interference wave measuring device according to the embodiment will be described with reference to FIG. FIG. 20 is a flowchart showing an example of processing executed by the radiation interference wave measuring device according to the embodiment.

In step S10, the radiation interference wave measuring device 1 accepts the input of the measurement conditions. The measurement conditions referred to here are, for example, the frequency band of the radiation interference wave for measuring the electric field strength, the measurement range in the height direction with respect to the ground plane, the distance between the measurement points in the height direction, the measurement range in the angular direction, and the angle. The interval between measurement points in the direction, the sampling time, the detection method of the receiving unit 30, and the frequency resolution bandwidth.

In step S20, the correction coefficient calculation function 202 selects the formula used for calculating the correction coefficient. Details of step S20 will be described later.

In step S30, the measurement height calculation function 203 calculates the height of the antenna for measuring the electric field using the correction coefficient calculated using the formula selected in step S20.

In step S40, the controller 15 changes the height of the antenna 11 to a height at which the electric field strength of the measurement point arranged at the lowest height can be measured, and the measurement point arranged at the position having the smallest angle. The turntable 13 is rotated to an angle at which the electric field strength of the above can be measured.

In step S50, the radiation interference wave measuring device 1 measures the electric field strength in a predetermined frequency band at each measurement point while rotating the turntable 13 while maintaining the height of the antenna 11 with respect to the specimen 100. Execute.

In step S60, the radiated jamming wave measuring device 1 determines whether or not the current turntable angle is the upper limit. When the radiation interference wave measuring device 1 determines that the current turntable angle is the upper limit (step S60: YES), the process proceeds to step S70, and when it is determined that the current turntable angle is not the upper limit (step S60: YES). Step S60: NO), the process is returned to step S50.

In step S70, the controller 15 raises the height of the antenna 11.

In step S80, the radiation interference wave measuring device 1 determines whether or not the current height of the antenna is the upper limit. When the radiation interference wave measuring device 1 determines that the height of the current antenna is the upper limit (step S80: YES), the process proceeds to step S90, and when it is determined that the height of the current antenna is not the upper limit (step S80: YES). Step S80: NO), the process is returned to step S50.

In step S90, the radiation interference wave measuring device 1 interpolates zero in the electric field strength between the measuring points.

In step S100, the radiation interference wave measuring device 1 applies a low-pass filter having a cutoff frequency calculated in step S90 to the pre-interference electric field intensity distribution with zeros inserted in step S90 to generate a post-interference electric field intensity distribution.

In step S110, the radiation interference wave measuring device 1 acquires data indicating the height of the antenna and the angle of the turntable, which are the maximum electric field strengths in the post-interpolated electric field strength distribution generated in step S100.

Next, with reference to FIG. 21, the details of step S20 shown in FIG. 20, that is, an example of the process in which the radiation interference wave measuring device according to the embodiment calculates the correction coefficient will be described. FIG. 21 is a flowchart showing an example of a process in which the radiation interference wave measuring device according to the embodiment selects an expression for calculating a correction coefficient.

In step S210, the correction coefficient calculation function 202 determines whether or not the radiation interference wave measuring device determines the formula used for calculating the correction coefficient. When the correction coefficient calculation function 202 determines that the radiation interference wave measuring device determines the formula used for calculating the correction coefficient (step S210: YES), the process proceeds to step S220, and the formula used for calculating the correction coefficient is used. If it is determined that the radiation interference wave measuring device does not determine (step S210: NO), the process proceeds to step S240.

In step S220, the correction coefficient calculation function 202 determines whether or not it is necessary to consider the radiated interference wave reflected on the floor surface. When the correction coefficient calculation function 202 determines that it is necessary to consider the radiation interference wave reflected on the floor surface (step S220: YES), the process proceeds to step S240, and the radiation interference wave reflected on the floor surface is removed. When it is determined that it is not necessary to consider (step S220: NO), the process proceeds to step S230. Specifically, the correction coefficient calculation function 202 executes the determination based on the determination of any of the above.

In step S230, the correction coefficient calculation function 202 selects the above-mentioned equation (20).

In step S240, the correction coefficient calculation function 202 selects the above-mentioned equation (23).

The radiation interference wave measuring device 1 according to the embodiment has been described above. The radiation interference wave measuring device 1 is based on the relative positional relationship between the specimen 100 including the radiation source that emits the radiation interference wave and the antenna 11 that performs the measurement of the electric field of the radiation interference wave, and the height of the antenna 11 is increased. It is provided with a correction coefficient calculation function 202 that calculates a correction coefficient whose interval satisfies the sampling theorem, and a measurement height calculation function 203 that sequentially calculates the height of the antenna when the measurement is performed using the correction coefficient. .. Therefore, the radiated interference wave measuring device 1 can narrow down the height of the antenna 11 that needs to measure the electric field, and can shorten the time required to carry out the radiated interference wave test.

Further, the radiation interference wave measuring device 1 includes a computer that executes a determination function 201 that determines whether or not it is necessary to consider the radiation interference wave reflected on the floor surface. Therefore, the radiation interference wave measuring device 1 selects an appropriate formula according to whether or not it is necessary to measure the electric field in consideration of the radiation interference wave reflected on the floor surface, and calculates an accurate correction coefficient. , The above-mentioned effects can be achieved.

In the above-described embodiment, the case where the radiation interference wave measuring device 1 measures the electric field strength at the measurement point and generates the electric field strength distribution after interpolation has been described as an example, but the present invention is not limited to this. For example, the radiated interference wave measuring device 1 may measure the magnetic field strength at the measurement point and apply the low-pass filter described above to the magnetic field strength distribution before interpolation to generate the magnetic field strength distribution after interpolation. Alternatively, the radiation interference wave measuring device 1 measures not the electric field strength but the value corresponding to the content of the absolute value symbol of the equation on the right side of the first equal sign of the above equation (2), and measures the distribution of the value. Then, the above-mentioned low-pass filter may be applied to the distribution of the values for interpolation.

Further, when the correction coefficient calculation function 202 determines that it is necessary to consider the radiated interference wave reflected on the floor surface, instead of calculating the correction coefficient K _hmax using the above equation (23), the correction coefficient calculation function 202 The calculation of the correction coefficient K _hmax may be stopped. Further, in this case, the correction coefficient calculation function 202 may control the radiation interference wave measuring device 1 to notify that it is necessary to consider the radiation interference wave reflected on the floor surface.

Further, the correction coefficient calculation function 202 may calculate the correction coefficient using the equation (23) regardless of whether or not it is necessary to consider the radiated interference wave reflected on the floor surface.

Further, the above-mentioned radiation interference wave may be emitted not from the specimen 100 but from a radiation source set assuming the radiation interference wave.

Further, a program for realizing each function of the controller 15, the control unit 20, and the receiving unit 30 according to the above-described embodiment is recorded on a computer-readable recording medium, and the program recorded on the recording medium is recorded in the computer system. Processing may be performed by reading and executing. Further, in particular, this recording medium is for causing a computer to execute the determination function 201, the correction coefficient calculation function 202, the measurement height calculation function 203, the first electromagnetic field distribution acquisition function 204, and the second electromagnetic field distribution acquisition function 205. The electromagnetic field distribution generation program may be stored.

The computer system referred to here may include hardware such as an operating system (OS) or peripheral devices. The computer-readable recording medium includes, for example, a floppy disk, a photomagnetic disk, a ROM (Read Only Memory), a writable non-volatile memory such as a flash memory, and a portable medium such as a DVD (Digital Versatile Disc). A computer system that holds a program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or client when a program is transmitted via a storage device such as a hard disk built into the computer system, a network, or a communication line. Also includes.

Further, the above-mentioned program may be transmitted from a computer system in which this program is stored in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the transmission medium for transmitting a program means a medium having a function of transmitting information, such as a network such as the Internet or a communication line such as a telephone line.

Further, the above-mentioned program may be for realizing a part of the above-mentioned functions, and is a so-called difference program which can realize the above-mentioned functions in combination with a program already recorded in the computer system. There may be. The above-mentioned program is read and executed by a processor such as a CPU (Central Processing Unit) provided in the computer, for example.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and various modifications, substitutions or designs are made without departing from the gist of the present invention. You can make changes. Further, the configurations described in the above-described embodiments may be combined.

1 ... Electromagnetic field measuring device, 11 ... Antenna, 12 ... Antenna mast, 13 ... Turntable, 14 ... Radio absorber, 15 ... Controller, 151 ... Height changing unit, 152 ... Direction changing unit, 20 ... Control unit, 201 ... Judgment function, 202 ... Correction coefficient calculation function, 203 ... Measurement height calculation function, 204 ... First electromagnetic field distribution acquisition function, 205 ... Second electromagnetic field distribution acquisition function, 210 ... Main controller, 220 ... Input device , 230 ... Output device, 240 ... Storage device, 245 ... Storage medium, 250 ... Bus, 30 ... Receiver, 100 ... Specimen, 200 ... Unit

Claims (17)

1. The relative positional relationship between the specimen containing the radiation source that emits the radiating interfering wave and the antenna that performs measurement of at least one of the electric and magnetic fields of the radiating interfering wave and on the floor surface on which the specimen is placed. A correction coefficient calculation function that calculates a correction coefficient in which the height interval of the antenna satisfies the sampling theorem based on the reflection coefficient of the radiated interfering wave.
   A measurement height calculation function that sequentially calculates the height of the antenna when the measurement is performed using the correction coefficient, and a measurement height calculation function.
   An electromagnetic wave measurement point calculation program that causes a computer to execute.
2. The correction coefficient calculation function includes the shortest horizontal distance between the test piece and the antenna, the longest horizontal distance between the test piece and the antenna, and the test piece from the floor on which the test piece is placed. It is a function to calculate the correction coefficient using at least two of the shortest distance to the test piece and the longest distance from the floor surface on which the test piece is placed to the test piece.
   The electromagnetic wave measurement point calculation program according to claim 1.
3. The correction coefficient calculation function calculates the correction coefficient using the following equation (1) or equation (2) and equation (3).
   The measurement height calculation function sequentially calculates the height of the antenna when the measurement is performed using the following equation (4).
   The electromagnetic wave measurement point calculation program according to claim 2.
   

   

   

   

   K _hmax : Correction coefficient h _rx : Antenna height d _min : Shortest horizontal distance between the specimen and the antenna d _max : _Longest horizontal distance between the specimen and the antenna h _min : The specimen is placed The shortest distance from the floor surface to the specimen h _max : The longest distance from the floor surface on which the specimen is placed to the specimen Δh _rx : The amount of change in the height of the antenna
   

   

   h _{rx_min} : Minimum value of antenna height
4. Further, the computer is made to execute a determination function for determining whether or not it is necessary to consider the radiation interference wave reflected on the floor surface.
   When it is determined that it is not necessary to consider the radiation interference wave reflected on the floor surface, the correction coefficient calculation function calculates the correction coefficient using the equation (1).
   The electromagnetic wave measurement point calculation program according to claim 3.
5. Further, the computer is made to execute a determination function for determining whether or not it is necessary to consider the radiation interference wave reflected on the floor surface.
   When the correction coefficient calculation function determines that it is necessary to consider the radiation interference wave reflected on the floor surface, the correction coefficient is calculated by using the equation (2), or the correction coefficient is calculated. Stop the calculation of
   The electromagnetic wave measurement point calculation program according to claim 3.
6. The correction coefficient calculation function calculates the correction coefficient using the equation (2) regardless of whether or not it is necessary to consider the radiation interference wave reflected on the floor surface.
   The electromagnetic wave measurement point calculation program according to claim 3.
7. The first electromagnetic field distribution acquisition function that acquires the first electromagnetic field distribution obtained by simulation or actual measurement, which is the distribution of at least one of the electric and magnetic fields of the radiated interfering wave.
   The electric field or magnetic field at the height of the antenna calculated by the measurement height calculation function is acquired by simulation or actual measurement, and is different from the height of the antenna calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function that acquires the second electromagnetic field distribution obtained by interpolating the electric field or magnetic field at the height of the antenna, and
   Let the computer do more
   The determination function calculates a deviation between the maximum value of the electric field or magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or magnetic field in the second electromagnetic field distribution, and the deviation is equal to or less than a predetermined allowable value. In this case, it is a function of determining that it is not necessary to consider the radiated interfering wave reflected on the floor surface.
   The electromagnetic wave measurement point calculation program according to claim 4.
8. The first electromagnetic field distribution acquisition function that acquires the first electromagnetic field distribution obtained by simulation or actual measurement, which is the distribution of at least one of the electric and magnetic fields of the radiated interfering wave.
   The electric field or magnetic field at the height of the antenna calculated by the measurement height calculation function is acquired by simulation or actual measurement, and is different from the height of the antenna calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function that acquires the second electromagnetic field distribution obtained by interpolating the electric field or magnetic field at the height of the antenna, and
   Let the computer do more
   The determination function calculates a deviation between the maximum value of the electric field or magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or magnetic field in the second electromagnetic field distribution, and the deviation exceeds a predetermined allowable value. If so, it is a function to determine that it is necessary to consider the radiated interfering wave reflected on the floor surface.
   The electromagnetic wave measurement point calculation program according to claim 5.
9. The first electromagnetic field distribution acquisition function that acquires the first electromagnetic field distribution obtained by simulation or actual measurement, which is the distribution of at least one of the electric and magnetic fields of the radiated interfering wave.
   The electric field or magnetic field at the height of the antenna calculated by the measurement height calculation function is acquired by simulation or actual measurement, and is different from the height of the antenna calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function that acquires the second electromagnetic field distribution obtained by interpolating the electric field or magnetic field at the height of the antenna, and
   Let the computer do more
   The determination function calculates the deviation between the maximum value of the electric field or magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or magnetic field in the second electromagnetic field distribution, and the reflection whose deviation is equal to or less than a predetermined threshold value. When it corresponds to the coefficient, it is a function to determine that it is not necessary to consider the radiated interfering wave reflected on the floor surface.
   The electromagnetic wave measurement point calculation program according to claim 4.
10. The first electromagnetic field distribution acquisition function that acquires the first electromagnetic field distribution obtained by simulation or actual measurement, which is the distribution of at least one of the electric and magnetic fields of the radiated interfering wave.
    The electric field or magnetic field at the height of the antenna calculated by the measurement height calculation function is acquired by simulation or actual measurement, and is different from the height of the antenna calculated by the measurement height calculation function using a low-pass filter. The second electromagnetic field distribution acquisition function that acquires the second electromagnetic field distribution obtained by interpolating the electric field or magnetic field at the height of the antenna, and
    Let the computer do more
    The determination function calculates the deviation between the maximum value of the electric field or magnetic field in the first electromagnetic field distribution and the maximum value of the electric field or magnetic field in the second electromagnetic field distribution, and the reflection in which the deviation exceeds a predetermined threshold value. When it corresponds to the coefficient, it is a function to determine that it is necessary to consider the radiated interfering wave reflected on the floor surface.
    The electromagnetic wave measurement point calculation program according to claim 5.
11. In the determination function, when the sampling frequency calculated from the reflection coefficient, the frequency of the radiated interfering wave and the maximum frequency of the radiating interfering wave satisfies the following equation (5), the radiation reflected on the floor surface. It is a function to judge that it is not necessary to consider the interference wave,
    The electromagnetic wave measurement point calculation program according to claim 4.
    

    
12. The determination function is reflected on the floor surface when the sampling frequency calculated from the reflection coefficient, the frequency of the radiating interfering wave and the maximum frequency of the radiating interfering wave does not satisfy the following equation (6). It is a function to judge that it is necessary to consider the radiated interference wave,
    The electromagnetic wave measurement point calculation program according to claim 5.
    

    
13. The determination function is reflected by the floor surface when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave at which at least one of the electric field and the magnetic field is measured satisfies the following equation (7). It is a function to judge that it is not necessary to consider radiated interference waves.
    The electromagnetic wave measurement point calculation program according to claim 4.
    

    
14. The determination function is reflected by the floor surface when the absorption characteristic of the floor surface with respect to the frequency of the radiated interfering wave at which at least one of the electric field and the magnetic field is measured does not satisfy the following equation (8). This is a function for determining that it is necessary to consider the radiated interference wave.
    The electromagnetic wave measurement point calculation program according to claim 5.
    

    
15. The determination function is performed when a radio wave absorber having a height of 0.45 λ _{min or} 2.8 λ _max with respect to the floor surface, whichever is larger than the larger value, is laid on the floor surface. It is a function to judge that it is not necessary to consider the radiation interference wave reflected by.
    The electromagnetic wave measurement point calculation program according to claim 4.
16. The determination function is performed when a radio wave absorber whose height with respect to the floor surface is less than the larger value of 0.45λ _min and 2.8λ _max is laid on the floor surface or when the radio wave absorber is installed. When it is not laid, it is a function to determine that it is necessary to consider the radiation interference wave reflected on the floor surface.
    The electromagnetic wave measurement point calculation program according to claim 5.
17. A radiated interference wave measuring device including a computer that executes the electromagnetic wave measuring point calculation program according to any one of claims 1 to 16.

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